1. Field of the Invention
An exemplary embodiment relates to an organic light emitting device and a method of fabricating the same.
2. Discussion of the Related Art
Recently, flat panel display devices such as a liquid crystal display, an organic light emitting device, and a plasma display panel have been receiving much attention because the flat panel display devices can solve defects of a related art display device such as a cathode ray tube.
In particular, because the organic light emitting device has a self-emitting structure that emits light without a light source such as a backlight unit, the organic light emitting device can be fabricated through a simple process to be light and thin. The organic light emitting device has been considered as the next generation display device due to characteristics such as a low drive voltage, a high emitting efficiency, and a wide viewing angle.
The organic light emitting device is fabricated by attaching an organic light emitting element array substrate provided with a plurality of organic light emitting elements to an encapsulation substrate for enclosing the organic light emitting element array substrate, scribing the attached structure along one or more organic light emitting elements, and performing a module process.
The organic light emitting element array substrate may be fabricated through the following process. Because the fabrication process is widely known in the related art, the fabrication process is described briefly.
A thin film transistor is formed on each subfield of a substrate. The thin film transistor may include a semiconductor layer, a gate insulating layer, a gate electrode, an interlayer dielectric layer, a source electrode, and a drain electrode.
A protective layer is formed on the thin film transistor, and then a first electrode is formed on the protective layer to be electrically connected to the drain electrode of the thin film transistor by passing through the protective layer. Hence, a thin film transistor array substrate including the thin film transistors and the corresponding first electrodes is formed.
Next, the thin film transistor array substrate is scribed to be separated into a plurality of substrate structures. Then an organic light emitting diode including an organic light emitting layer and a second electrode is fabricated on the first electrode, and the organic light emitting element array substrate is attached to the encapsulation substrate. Next, the attached structure is scribed, and then the module process is performed to fabricate the individual organic light emitting devices.
As described above, before the organic light emitting layer is formed on the first electrodes, the mother substrate having the thin film transistors and the first electrodes is scribed, for the convenience of fabrication process, to be separated into the plurality of substrate structures, each having a desired size. Next, these substrate structures go through a grinding process. However, a foreign material such as glass chips or particles is generated during the scribing process or the grinding process, and gets attached to the surface of the first electrodes and the surface of a power line provided in the substrate structures. The attached foreign materials may reduce electrical characteristics of the first electrodes, and/or form poor organic light emitting layers in a succeeding formation process for the organic light emitting layers. For instance, black spots may be generated in the organic light emitting device, the surface of the power line may be polluted, and resistance characteristics may be changed to be undesirable.